LOL! Well perhaps Linux From Scratch would be something that would suit you well?
Anyway, you should have no problems building xchat from source if you have gtk+ 2.0 or 2.2 and the corresponding development libraries installed.
If you're running MDK 9.1 it looks like it should be these:
libgtk+2.0_0-2.2.1-2mdk.i586.rpm
libgtk+2.0_0-devel-2.2.1-2mdk.i586.rpm
...and also glib:
libglib2.0_0-2.2.1-1mdk.i586.rpm
libglib2.0_0-devel-2.2.1-1mdk.i586.rpm
Doesn't Mandrake come with a package manager where you can just chose what package to install and dependency packages are installed automatically? That should help.
Håkan